blowby etc
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From: Norn Iron
blowby etc My engine rebuild is pretty recent. New pistons, honed block to 383. I did kinda damage a few pistons and rings, so had to rebuild. This only ran for a few hundred miles.
I used a new set of rings, but did not touch the bores at all. 4 pistons were replaced.
Ive driven it for about 500 miles on normal oil, quite easy ( it rains a lot ) no real load on the engine. But the engine is breathing heavier than Im happy with.
I just added in a pair of -10 breathers to the valley cover to help alleviate any pressure that may happen to be in there.. It isnt chucking oil BTW though....mostly mayo crap ( car runs at 175degF during normal driving ) but Im putting this down to condensation due to the cold stat..
When I changed the oil yesterday to some decent stuff, the oil itself kinda stunk of exhaust gasses. I had it sitting at idle for about 10 mins before changing the oil, to warm it up.
When I built it, the ring clearances were pretty tight, so I dont think the ring gap is an issue. ( Total seal 1 piece stainless top, and Napier 2nd ) I got them within about 2 thou of the specs supplied with the rings...which were tight at around 16 thou ( give or take...dont have the specs to hand )
Although I did kinda break one 2nd ring when installing, so had to re-use an old 2nd ring, which was say 23thou ( not napier ) These only had a few hundred miles though.
Would this seem odd ? And should I be concerned ? or am I maybe being paranoid. I dont recall oil smelling like that when ive changed it before, although I usually change it after a drive..
It isnt using oil, and it runs fine.
I used a new set of rings, but did not touch the bores at all. 4 pistons were replaced.
Ive driven it for about 500 miles on normal oil, quite easy ( it rains a lot ) no real load on the engine. But the engine is breathing heavier than Im happy with.
I just added in a pair of -10 breathers to the valley cover to help alleviate any pressure that may happen to be in there.. It isnt chucking oil BTW though....mostly mayo crap ( car runs at 175degF during normal driving ) but Im putting this down to condensation due to the cold stat..
When I changed the oil yesterday to some decent stuff, the oil itself kinda stunk of exhaust gasses. I had it sitting at idle for about 10 mins before changing the oil, to warm it up.
When I built it, the ring clearances were pretty tight, so I dont think the ring gap is an issue. ( Total seal 1 piece stainless top, and Napier 2nd ) I got them within about 2 thou of the specs supplied with the rings...which were tight at around 16 thou ( give or take...dont have the specs to hand )
Although I did kinda break one 2nd ring when installing, so had to re-use an old 2nd ring, which was say 23thou ( not napier ) These only had a few hundred miles though.
Would this seem odd ? And should I be concerned ? or am I maybe being paranoid. I dont recall oil smelling like that when ive changed it before, although I usually change it after a drive..
It isnt using oil, and it runs fine.
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From: sneaking in your back door as you leave!/cartersville ga
i think you should have at least took a honing brush to the cylinder walls to get the glaze off of them, before you put the new rings in. honing ensures good ring break-in
I think it was a bad idea to use stainless rings on a used bore. Hard enough to get them to seat well on a nicely prepped bore sometimes..
But yes the oil smelling like exhaust with low miles is a good sign of blowby, running rich, or not getting the oil up to temp. Leakdown test wouldnt be a bad idea.
But yes the oil smelling like exhaust with low miles is a good sign of blowby, running rich, or not getting the oil up to temp. Leakdown test wouldnt be a bad idea.
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From: Norn Iron
The bores literally had about 500 miles since a proper hone which took them to 3.905. So I felt no reason to touch the bore, which was fine at that time, until I blew it up ( the DIY head shimming then revving incident etc which lead to warped top rings )
Used...yes, but at 500 miles ( most of which were very easy ) shouldnt the bore still be perfect ?
Very good chance the oil isnt getting up to temp. The engine is running cold due to the stat ( and of course I ordered some from Summit...and the one they sell for "late model LS1" is totally wrong
Dont have a leakdown tester, but I will get one soon enough.
When I checked the new breather cans I fitted to the valve cover....after say 80 easy miles today, there is about 3/4" of relatively clean water in each of them.
Used...yes, but at 500 miles ( most of which were very easy ) shouldnt the bore still be perfect ?
Very good chance the oil isnt getting up to temp. The engine is running cold due to the stat ( and of course I ordered some from Summit...and the one they sell for "late model LS1" is totally wrong
Dont have a leakdown tester, but I will get one soon enough.
When I checked the new breather cans I fitted to the valve cover....after say 80 easy miles today, there is about 3/4" of relatively clean water in each of them.
No PCV + cold and damp = water in the breathers on an all aluminum engine.
Stainless rings are very touchy with cylinder wall prep, nothing you do now except put some miles on it and check the leakdown.
Stainless rings are very touchy with cylinder wall prep, nothing you do now except put some miles on it and check the leakdown.
good thing is no one usually has to walk home from blowby 
Good indication is watching the breathers on the dyno, if it looks like a steam train at WOT then you might have some issues. As long as the oil rings are doing their job a little blowby wont kill power too bad.
Good indication is watching the breathers on the dyno, if it looks like a steam train at WOT then you might have some issues. As long as the oil rings are doing their job a little blowby wont kill power too bad.
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I never pull a piston and use old rings, I never install rings without a good hone. Your rings are not sealing, they probly never will now. You got a new engine that thinks it has 100,000 miles on it. Check your compression and I bet it will be low. If you know you broke one during piston install, you might even have another broken that you do not know about. A compression check should tell you that. Pull your plugs and see if they are starting to oil foil. Bet they are. Sorry man, not trying to flame, but changing rings without honing is a bad idea. I know you stated the engine only had 500 miles on it, but cyl. will start to glaze over and break in to the new rings in a very short time with a good hone job. The only thing I can think of short of pulling the engine and reduing it right with another set of rings, is you can try to load the rings. You will have to realy load the engine hard. I would not do this until after you have checked for a broken ring witha compression check and a leak down check. If all cyls. are good but one, you probly have a broken ring. If they arfe all the same, but low, try loading it hard multiple times.
I might be wrong though. I am a profetional mechanic (hince the miss spelled words), and have been for 20 years.
Sorry dude, good luck.
I might be wrong though. I am a profetional mechanic (hince the miss spelled words), and have been for 20 years.
Sorry dude, good luck.
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9 Second Club
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From: Norn Iron
Wont be hard to load it up...Im taking it to a dyno on Friday lol.
I am 100% certain only one ring broke.....simply my negligence, and a crap spring compressor...and newly machined deck. Stupid for not chamfering the top of the bores.
I did just change the plugs from TR6's that I was using for the first few hundred miles. The plugs are perfectly normal, no odd colouring, or anything to suggest any oil contamination..
I am 100% certain only one ring broke.....simply my negligence, and a crap spring compressor...and newly machined deck. Stupid for not chamfering the top of the bores.
I did just change the plugs from TR6's that I was using for the first few hundred miles. The plugs are perfectly normal, no odd colouring, or anything to suggest any oil contamination..
500 miles will not affect the bore of the block, but the hatch pattern of the hone will have worn down. The hatch pattern of the hone is really important for seating the rings 'quickly'. If you did not rehone the block, the rings will still seat but will take a while longer to do so.
Keith
Keith
